A Magnetic Random Access Memory (MRAM) includes a Magnetic Tunnel Junction (MTJ) element which according to a magneto-resistive effect has a resistance value that is variable due to magnetized states of two magnetic layers that are used as memory elements.
In order to make the MRAM practical, it is necessary to increase its capacity, and to reduce a chip size thereof. In order to realize such goals, it is preferable to further minimize memory cell array size, that is, to further minimize the size of the MTJ element.
In order for the MTJ element to stably retain information for a long period of time, its magnetic layer should have a predetermined thermal disturbance constant. Accordingly, even when the size of the MTJ element is minimized, it is necessary to secure a sufficient thermal disturbance constant.